Observation of the Josephson effect in Pb/(Ba,K)Fe2As2 single crystal junctions

Abstract

We have fabricated c-axis Josephson junctions on single crystals of (Ba,K)Fe2As2 by using Pb as the counter electrode in two geometries, planar and point contact. Junctions in both geometries show resistively shunted junction I-V curves below the Tc of the counter electrode. Microwave induced steps were observed in the I-V curves, and the critical currents are suppressed with an in-plane magnetic field in a manner consistent with the small junction limit. ICRN products of up to 0.3 mV have been observed in these junctions at 4.2 K. The observation of Josephson coupling along the c-axis between (Ba,K)Fe2As2 and a conventional superconductor suggests the existence of a s-wave superconducting order parameter in this class of iron pnictide superconductors.

16 pages and 3 figures

References in corpus (21)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Anisotropic thermodynamic and transport properties of single crystalline (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$ (x = 0 and 0.45)
• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• The BCS-like gap in superconductor SmFeAsO_0.85F_0.15
• Multiband magnetism and superconductivity in Fe-based compounds
• Electron Correlations in the Low Carrier Density LaFeAsO0.89F0.11 Superconductor (Tc = 28 K)
• Spin-triplet p-wave pairing in a 3-orbital model for iron pnictide superconductors
• Probing superconducting energy gap from infrared spectroscopy on a Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ single crystal with T${}_c$=37 K
• Superconducting properties of Fe-based layered superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs
• Even Parity, Orbital Singlet and Spin Triplet Pairing for Superconducting $La(O_{1-x}{F}_x)FeAs$
• Point-Contact Spectroscopy of Iron-Based Layered Superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs
• Scanning tunneling spectroscopy of SmFeAsO0.85: Possible evidence for d-wave order parameter symmetry
• Limits on the Superconducting Order Parameter in NdFeAsO${}_{1-x}$F${}_y$ from Scanning SQUID Microscopy
• Investigation of Superconducting Gap Structure in TbFeAsO${}_{0.9}$F${}_{0.1}$ using Point Contact Andreev Reflection
• Scanning tunneling microscopy of the 32 K superconductor (Sr1-xKx)Fe2As2
• Nodeless superconducting gap in NdFeAsO${}_{0.9}$F${}_{0.1}$ single crystals from anisotropic penetration depth studies

Cited by in corpus (12)

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• Calorimetric Evidence of Strong-Coupling Multiband Superconductivity in Fe(Te0.57Se0.43) Single Crystal
• BaFe_{1.8}Co_{0.2}As_2 thin film hybrid Josephson junctions
• $\pi$-junction to probe antiphase s-wave pairing in iron pnictide superconductors
• Josephson effect between electron-doped and hole-doped iron pnictide single crystals
• Evidence of a universal and isotropic 2Δ/kBTC ratio in 122-type iron pnictide superconductors over a wide doping range
• Metastable $\pi$-junction between an s${}_{\pm }$-wave and an s-wave superconductor
• Shapiro Steps as a Direct Probe of $\pm s$-wave Symmetry in Multi-gap Superconducting Josephson Junctions
• Quasiclassical description of a superconductor with a spin density wave
• Macroscopic quantum tunneling in multigap superconducting Josephson junctions: Escape rate enhancement via quantum fluctuations of Josephson-Leggett mode
• Possible pi-phase shift at interface of two pnictides with antiphase s-wave pairing
• Anomalous Tail Effect on Resistivity Transition and Weak-link Behavior of Iron Based Superconductor